The Designated Senior Official (DSO), also referred to as the Senior Designated Official (SDO) or Designated Civilian Official (DCO), is an additional duty or responsibility assigned to officials within governments. The designation, often mandated in legislation, requires the official to take a direct role in a priority initiative, program, or project, ensuring that sufficient importance, support and oversight is provided. The terminology, level of seniority, and reporting requirements varies depending on the context, the legislation, and the agency or department the individual represents.